1. Field of the Invention
The invention relates to an attachment mechanism for a vehicle part to a vehicle, such as for a vehicle light to a vehicle body. More particularly, the invention relates to an attachment mechanism that is made up of components that can be easily sorted that disposal and recycling of the mechanism is facilitated at the end of its useful life. Also, the attachment mechanism is capable of providing secure attachment of the vehicle light to the vehicle body.
2. Discussion of the Related Art
FIG. 4 illustrates a conventional attachment mechanism 90 for a vehicle light 10 to a vehicle body 20. The attachment mechanism 90 includes a housing 11 for a vehicle light 10. The housing 11 is made up of the following components: a rib 12 along the perimeter of outer back portion of housing 11; three stud bolts 91 positioned inside the rib 12; three through holes positioned inside the stud bolts 91 for attachment of a light bulb to the housing 11; and a gasket 13 interposed between the housing 11 and the vehicle body 20. The vehicle body 20 and housing 11 include three through holes 92 corresponding to the stud bolts 91 and three nuts 93 which correspond to the stud bolts 91 and are attached from inside of the vehicle body 20. Each stud bolt 91 is inserted and fixed in the housing 11 by insertion molding or by a pressing process using ultrasonic waves. Each stud bolt 91 is inserted from outside of the vehicle body 20, through a predetermined through hole on a gasket 13, to the predetermined through hole 92 in the vehicle body 20. The stud bolts 91 is fixed by a nut 93 from inside of the vehicle body 20 which presses the gasket 13 onto 12 of housing 11.
FIG. 5 illustrates another conventional attachment mechanism for a vehicle light 10 to a vehicle body 20. The vehicle light 10 includes a housing 11 having an aperture for the purpose of changing a light bulb in the housing 11. A pair of elastic hooks 94 project from the outer back surface of the housing 11 and are made of plastic resin--which is the same material as comprises housing 11. The vehicle light 10 is attached to the vehicle body 20 by being pushed from outside of the vehicle body 20 into an aperture 95 in the vehicle body 20. When the vehicle light 10 is pushed in, the elastic hook 94 curves and returns to its original position by its elasticity. Thus, the elastic hook 94 latches onto the attachment portion of vehicle body 20.
The conventional attachment mechanisms for attaching a vehicle light to a vehicle body have the following problems. The attachment mechanism 90 in FIG. 4 is able to provide a secured attachment by using a stud bolt 91. However, the stud bolt 91 is usually metal that is strongly adhered to surrounding portions of the housing, which are made of resin. Accordingly, when the vehicle light 10 is disposed of and destroyed, it is difficult to deconstruct and sort each of the vehicle light's components for recycling without damaging the resin plastic material. In addition, the various materials required to construct the attachment mechanism increase the cost of manufacture and sale of the mechanism.
The attachment mechanism shown in FIG. 5 does not have the same sorting problem during recycling of the device as does the mechanism of FIG. 4. However, since the hook 94 is elastic and designed to curve in a Z direction parallel to the vehicle body 20, and is oriented in a direction of engagement between the elastic hook 94 and the vehicle body 20, the attachment mechanism has relatively low shock-proof reliability when an external force is applied in the Z direction. For example, if a concentration of force is applied in the Z direction and one of the pair of elastic hooks 94 flexes, the other elastic hook 94 easily detaches from the aperture, and the vehicle light 10 may detach from the vehicle body 20.